1. Field of the Invention
The present invention relates to a lens hood attachable to a lens barrel.
2. Description of the Related Art
Conventionally, a lens hood is attached to a front end portion of a lens barrel to shield a camera lens from unwanted light coming from outside the angle of view of image-capturing, which causes flare and ghost. Further, various types of filters such as a polarization filter, a neutral density (ND) filter, a cross filter are attached to the front end portion of the lens barrel to increase photographic effects.
A rotation effect filter (optical member) is one of the various types of filters and can change the photographic effect by changing the position of rotation about an optical axis. In a case where a rotation effect filter is used in a single-lens reflex camera and the like, the photographer can check with a finder while changing the rotation position. Specifically, the configuration enables the photographer to check the photographic effect while performing rotational operation.
In general, a rotation effect filter includes a male screw member corresponding to a female screw member formed on an inner peripheral surface of a front end portion of a lens barrel, and the male screw member is screwed with the female screw member so that the rotation effect filter is attached to the front end portion of the lens barrel. Further, a lens hood is attached to the front end portion of the lens barrel by means of a structure (e.g., bayonet structure) provided on the outer peripheral surface of the front end portion of the lens barrel.
The lens hood is attached to the outer peripheral surface of the front end portion of the lens barrel and has a cylindrical shape including an opening on the side close to an object to be captured. Thus, the rotation effect filter attached to the inner peripheral surface of the front end portion of the lens barrel is covered around the optical axis by the lens hood.
Therefore, in order to perform rotational operation of the rotation effect filter when the lens hood is attached, the photographer needs to insert a finger into the opening of the lens hood on the side close to the object to be captured. Therefore, when the lens hood is attached, if the photographer operates the rotation effect filter while checking the object with a finder, light entering the lens barrel is partially blocked by the finger. This is not desirable for checking an image-capturing screen. Further, depending on the total length of the lens hood, it may be difficult to operate the rotary effect finder by inserting the finger into the opening on the side close to the object to be photographed.
To solve such a problem, U.S. Pat. No. 6,269,227 discusses a configuration including an opening through which a finger of the photographer can be inserted into a peripheral surface of a lens hood to operate a rotation effect filter and a lid member for closing the opening. Further, the lid member is linked to the lens hood by means of a hinge structure or trajectory structure (i.e., rail structure).